http://edition.cnn.com/2016/06/26/asia/africans-leaving-guangzhou-china/index.html
Basically, the most important reason for e nation to allow immigrants to get its nationality is whether those immigrants are profitable for the nation. That's one of the reasons why European countries are discussing what to do with immigrants or refugees from middle east countries.
By the way, Africans in Guangzhou interviewed on the article will benefit China?
They earned money by selling fake brands manufactured in China.
If they want to be authorized by China officials, they should earn within legal procedures.